How would you describe the sound of differant cones? Paper, Kevlar/Glass and metal?

Hoodlum007

03-03-2007, 12:53 PM

i am actually interested to know that as well.

Beat_Dominator

03-03-2007, 01:00 PM

From my experience, it's not that simple :crap: There are just too many factors in a driver design beyone the cone material.

Rattlebrain

03-03-2007, 01:11 PM

It may just be my imagination but I have always preferred the sound of paper cones. They just sound more "natural" to me.

IMO

leonsv

03-03-2007, 03:46 PM

this section of the review by npdang over at diyma should give you some idea

"7” mid/bass:

Seas RNX drivers – Comes in many flavors, but are essentially the same driver. The /p in the model# refers to a phaseplug. Model #’s are P for poly, L for aluminum, G for fiberglass, CA for paper. For example L18rnx/p refers to an aluminum cone with phaseplug.

Poly – Unlike Dynaudio for example, the Seas poly cone is a pure poly cone and unblended with mica or any other stiffening elements (IIRC). This yields a very well dampened cone that provides a smooth frequency and extremely forgiving nature at the expense of detail. Special note, the P18rnx/p is the only model to use the latest “adaptive surround” which is used on Seas higher end Excel drivers. The adaptive surround provides greater dampening at higher frequencies for a smoother response, and less dampening in the lower frequencies.

Aluminum – Provides the best detail retrieval, but has significant upper end breakup which should be attenuated to reduce coloration and distortion. Can be a difficult driver to work with, and should ideally be used below 2khz necessitating a high performance tweeter.

Fiberglass – This is the best compromise between detail and warmth. Robust sounding, but not overly laid back or heavy. Has excellent top end extension that will mate easily to any tweeter and requiring very little filtering up top. The only downside is that this unit has been discontinued and could be hard to find. Solen.ca usually has some stock.

Paper – A very warm, smooth, robust sounding midrange. Generally considered the most neutral sounding driver of the three, although detail retrieval is nearly as bad as the poly cone. Definitely has more character and presence than the poly. Good top end extension means this driver mates quite easily to any number of compact tweeters."

Gary S

03-03-2007, 07:07 PM

What a great question.

leonsv and beat_Dominator are correct.
Assuming everything else about the speaker is the same (which it never is, LOL! :D ), very generally:

- Paper (wood fiber, LOL!) cones tend to have reasonably decent velocity of sound propagation and damping... but they are fragile... get them wet and they can start to deteriorate very quickly.

- Polypropylene (plastic :D )... probably the most widely used material, probably because it is waterproof. Typically the worst sounding though... poor velocity, but great damping... crumple up an old milk carton... it will probably take a half-hour before it stops trying to return to it's molded shape.... nasty, LOL! But some of the poly cones with metal deposition on the front sound surprisingly good... such as quart... I don't know how they do it... it defies physics.

- Woven carbon fiber - high velocity, able to handle more complex sounds, but low damping... like metal cones, people describe the bass/midbass as snappy, rather than full and natural like a well-damped cone can potentially sound.

- metal cones - super high velocity of sound propagation, able to handle complex musical passages and deliver great detail, but poor damping.

- Kevlar, pressed man-made fibers, and foam or "foamed" cones - the best... above average velocity of sound propagation, and excellent damping. The Focals' with the foam or kevlar both have a foam core... legendary speakers at this point.

- Image Dynamics is coming out with a line of components with pressed ceramic fibers and foam... I'll bet they have "the right sound", if you will. I had heard about a speaker designer submitting a patent for ceramic mid-woofers a couple years ago... I guess the patent was approved.

More on it here:

http://www.northfieldmoorooka.com.au/content.php?contentID=79

But read Beat_Dominator's post again and memorize it.... drivers are very complex critters with too many different parameters... knowing the cone material, by itself, tells you very little.

Thnking

03-03-2007, 11:20 PM

The sound velocity is basically independent of cone material.
The differences in material determine resonant characteristics and cone flexing/strength.